The ultra-structure of the epidermis of larvae of the herring (Clupea harengus) in relation to the rearing salinity

The ultra-structure of the epidermis of herring larvae is described. It is composed of two cell layers ; the outer layer contains mitochondria, vesicles and a practically continuous layer having a dense 'fibrous' appearance. The cell border in contact with the sea water is thrown into an irregular arrangement of ridges and pits. The inner cell layer is usually thicker than the outer layer and lacks the continuous dense layer. No differences could be found in the structure or thickness of the epidermal cells of larvae reared in salinities of 5, 17·5, 35 and 50 ‰